Porygon-Z

Diamond +3: Additional software was installed to make it a better Pokémon. It began acting oddly, however.

Platinum +4: Its programming was modified to enable work in alien dimensions. It did not work as planned.

HeartGold +3: Its programming was modified to enable it to travel through alien dimensions. Seems there might have been an error...

Sun: In order to create a more advanced Pokémon, an additional program was installed, but apparently it contained a defect that makes it move oddly.

Moon: Its program was modified to facilitate extra-dimensional activities, but that led to noticeably strange behavior.

Ultra Sun: Its behavior is noticeably unstable, which is apparently due to the incompetence of the engineer who updated its programming.

Ultra Moon: A faulty update was added to its programming. Its behavior is noticeably strange, so the experiment may have been a failure.

Sword: Porygon-Z had a program installed to allow it to move between dimensions, but the program also caused instability in Porygon-Z’s behavior.

Shield: Some say an additional program made this Pokémon evolve, but even academics can’t agree on whether Porygon-Z is really an evolution.

Legends: Arceus: A curious item induced this evolution. The Pokémon's offensive capabilities have greatly increased, but the strangeness of its behavior has magnified in equal measure. This worries me.